// ImageEncoder - abstract class for writing out an image
//
// Copyright (C) 1996 by Jef Poskanzer <jef@acme.com>.  All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme.JPM.Encoders;

import java.util.*;
import java.io.*;
import java.awt.Image;
import java.awt.image.*;

/**
 * Abstract class for writing out an image.
 * <p>
 * A framework for classes that encode and write out an image in 
 * a particular file format.
 * </p>
 * <p>
 * This provides a simplified rendition of the ImageConsumer interface. 
 * It always delivers the pixels as ints in the RGBdefault color model.
 * It always provides them in top-down left-right order.
 * If you want more flexibility you can always implement ImageConsumer
 * directly.
 * </p>
 * @see GifEncoder
 * @see PpmEncoder
 * @see Acme.JPM.Decoders.ImageDecoder
 */
public abstract class ImageEncoder implements ImageConsumer
{

    protected OutputStream out;

    private ImageProducer producer;
    private int width = -1;
    private int height = -1;
    private int hintflags = 0;
    private boolean started = false;
    private boolean encoding;
    private IOException iox;
    private static final ColorModel rgbModel = ColorModel.getRGBdefault();
    private Hashtable props = null;

    /**
     * Constructor.
     * @param img The image to encode.
     * @param out The stream to write the bytes to.
     * @throws IOException
     */
    public ImageEncoder( Image img, OutputStream out ) throws IOException
    {
        this( img.getSource(), out );
    }

    /**
     * Constructor.
     * @param producer The ImageProducer to encode.
     * @param out The stream to write the bytes to.
     * @throws IOException
     */
    public ImageEncoder( ImageProducer producer, OutputStream out ) throws IOException
    {
        this.producer = producer;
        this.out = out;
    }


    // Methods that subclasses implement.

    /// Subclasses implement this to initialize an encoding.
    abstract void encodeStart( int w, int h ) throws IOException;

    /// Subclasses implement this to actually write out some bits.  They
    // are guaranteed to be delivered in top-down-left-right order.
    // One int per pixel, index is row * scansize + off + col,
    // RGBdefault (AARRGGBB) color model.
    abstract void encodePixels(
            int x, int y, int w, int h, int[] rgbPixels, int off, int scansize )
    throws IOException;

    /// Subclasses implement this to finish an encoding.
    abstract void encodeDone() throws IOException;


    // Our own methods.

    /**
     * Call this after initialization to get things going.
     * @throws IOException
     */ 
    public synchronized void encode() throws IOException
    {
        encoding = true;
        iox = null;
        producer.startProduction( this );
        while ( encoding )
            try
        {
                wait();
        }
        catch ( InterruptedException e ) {}
        if ( iox != null )
            throw iox;
    }

    private boolean accumulate = false;
    private int[] accumulator;

    private void encodePixelsWrapper(
            int x, int y, int w, int h, int[] rgbPixels, int off, int scansize )
    throws IOException
    {
        if ( ! started )
        {
            started = true;
            encodeStart( width, height );
            if ( ( hintflags & TOPDOWNLEFTRIGHT ) == 0 )
            {
                accumulate = true;
                accumulator = new int[width * height];
            }
        }
        if ( accumulate )
            for ( int row = 0; row < h; ++row )
                System.arraycopy(
                        rgbPixels, row * scansize + off,
                        accumulator, ( y + row ) * width + x,
                        w );
        else
            encodePixels( x, y, w, h, rgbPixels, off, scansize );
    }

    private void encodeFinish() throws IOException
    {
        if ( accumulate )
        {
            encodePixels( 0, 0, width, height, accumulator, 0, width );
            accumulator = null;
            accumulate = false;
        }
    }

    private synchronized void stop()
    {
        encoding = false;
        notifyAll();
    }


    // Methods from ImageConsumer.

    public void setDimensions( int width, int height )
    {
        this.width = width;
        this.height = height;
    }

    public void setProperties( Hashtable props )
    {
        this.props = props;
    }
    /**
     * Does nothing.
     * @param model
     * @see java.awt.image.ImageConsumer#setColorModel(java.awt.image.ColorModel)
     */
    public void setColorModel( ColorModel model )
    {
        // Ignore.
    }

    public void setHints( int hintflags )
    {
        this.hintflags = hintflags;
    }

    public void setPixels(
            int x, int y, int w, int h, ColorModel model, byte[] pixels,
            int off, int scansize )
    {
        int[] rgbPixels = new int[w];
        for ( int row = 0; row < h; ++row )
        {
            int rowOff = off + row * scansize;
            for ( int col = 0; col < w; ++col )
                rgbPixels[col] = model.getRGB( pixels[rowOff + col] & 0xff );
            try
            {
                encodePixelsWrapper( x, y + row, w, 1, rgbPixels, 0, w );
            }
            catch ( IOException e )
            {
                iox = e;
                stop();
                return;
            }
        }
    }

    public void setPixels(
            int x, int y, int w, int h, ColorModel model, int[] pixels,
            int off, int scansize )
    {
        if ( model == rgbModel )
        {
            try
            {
                encodePixelsWrapper( x, y, w, h, pixels, off, scansize );
            }
            catch ( IOException e )
            {
                iox = e;
                stop();
                return;
            }
        }
        else
        {
            int[] rgbPixels = new int[w];
            for ( int row = 0; row < h; ++row )
            {
                int rowOff = off + row * scansize;
                for ( int col = 0; col < w; ++col )
                    rgbPixels[col] = model.getRGB( pixels[rowOff + col] );
                try
                {
                    encodePixelsWrapper( x, y + row, w, 1, rgbPixels, 0, w );
                }
                catch ( IOException e )
                {
                    iox = e;
                    stop();
                    return;
                }
            }
        }
    }

    public void imageComplete( int status )
    {
        producer.removeConsumer( this );
        if ( status == ImageConsumer.IMAGEABORTED )
            iox = new IOException( "image aborted" );
        else
        {
            try
            {
                encodeFinish();
                encodeDone();
            }
            catch ( IOException e )
            {
                iox = e;
            }
        }
        stop();
    }

}
